From 10f5bff622cad71645e22c027b77ac31e51008ef Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Mon, 10 Feb 2014 14:48:51 +0800 Subject: util: Split out exec_dir from os_find_datadir With this change, main() calls qemu_init_exec_dir and uses argv[0] to init exec_dir. The saved value can be retrieved with qemu_get_exec_dir later. It will be reused by module loading. Signed-off-by: Fam Zheng Signed-off-by: Paolo Bonzini --- util/oslib-posix.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ util/oslib-win32.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 84 insertions(+) (limited to 'util') diff --git a/util/oslib-posix.c b/util/oslib-posix.c index d5dca4729a..c2eeb4fe40 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -57,6 +57,7 @@ extern int daemon(int, int); #include "trace.h" #include "qemu/sockets.h" #include +#include #ifdef CONFIG_LINUX #include @@ -274,3 +275,56 @@ void qemu_set_tty_echo(int fd, bool echo) tcsetattr(fd, TCSANOW, &tty); } + +static char exec_dir[PATH_MAX]; + +void qemu_init_exec_dir(const char *argv0) +{ + char *dir; + char *p = NULL; + char buf[PATH_MAX]; + + assert(!exec_dir[0]); + +#if defined(__linux__) + { + int len; + len = readlink("/proc/self/exe", buf, sizeof(buf) - 1); + if (len > 0) { + buf[len] = 0; + p = buf; + } + } +#elif defined(__FreeBSD__) + { + static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1}; + size_t len = sizeof(buf) - 1; + + *buf = '\0'; + if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) && + *buf) { + buf[sizeof(buf) - 1] = '\0'; + p = buf; + } + } +#endif + /* If we don't have any way of figuring out the actual executable + location then try argv[0]. */ + if (!p) { + if (!argv0) { + return; + } + p = realpath(argv0, buf); + if (!p) { + return; + } + } + dir = dirname(p); + + pstrcpy(exec_dir, sizeof(exec_dir), dir); +} + +char *qemu_get_exec_dir(void) +{ + return g_strdup(exec_dir); +} diff --git a/util/oslib-win32.c b/util/oslib-win32.c index 50be0440f2..93f7d351d3 100644 --- a/util/oslib-win32.c +++ b/util/oslib-win32.c @@ -208,3 +208,33 @@ void qemu_set_tty_echo(int fd, bool echo) dwMode & ~(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT)); } } + +static char exec_dir[PATH_MAX]; + +void qemu_init_exec_dir(const char *argv0) +{ + + char *p; + char buf[MAX_PATH]; + DWORD len; + + len = GetModuleFileName(NULL, buf, sizeof(buf) - 1); + if (len == 0) { + return; + } + + buf[len] = 0; + p = buf + len - 1; + while (p != buf && *p != '\\') { + p--; + } + *p = 0; + if (access(buf, R_OK) == 0) { + pstrcpy(exec_dir, sizeof(exec_dir), buf); + } +} + +char *qemu_get_exec_dir(void) +{ + return g_strdup(exec_dir); +} -- cgit v1.2.1 From e26110cfc67d48331a76e9b1e6f7fed7569e1ab3 Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Mon, 10 Feb 2014 14:48:57 +0800 Subject: module: implement module loading This patch adds loading, stamp checking and initialization of modules. The init function of dynamic module is no longer directly called as __attribute__((constructor)) in static linked version, it is called only after passed the checking of presense of stamp symbol: qemu_stamp_$RELEASEHASH where $RELEASEHASH is generated by hashing version strings and content of configure script. With this, modules built from a different tree/version/configure will not be loaded. The module loading code requires gmodule-2.0. Modules are searched under - CONFIG_MODDIR - executable folder (to allow running qemu-{img,io} in the build directory) - ../ of executable folder (to allow running system emulator in the build directory) Modules are linked under their subdir respectively, then copied to top level of build directory for above convinience, e.g.: $(BUILD_DIR)/block/curl.so -> $(BUILD_DIR)/block-curl.so Signed-off-by: Paolo Bonzini Signed-off-by: Fam Zheng Signed-off-by: Paolo Bonzini --- util/module.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 143 insertions(+), 2 deletions(-) (limited to 'util') diff --git a/util/module.c b/util/module.c index 7acc33d076..42bc3732c9 100644 --- a/util/module.c +++ b/util/module.c @@ -13,6 +13,8 @@ * GNU GPL, version 2 or (at your option) any later version. */ +#include +#include #include "qemu-common.h" #include "qemu/queue.h" #include "qemu/module.h" @@ -21,13 +23,16 @@ typedef struct ModuleEntry { void (*init)(void); QTAILQ_ENTRY(ModuleEntry) node; + module_init_type type; } ModuleEntry; typedef QTAILQ_HEAD(, ModuleEntry) ModuleTypeList; static ModuleTypeList init_type_list[MODULE_INIT_MAX]; -static void init_types(void) +static ModuleTypeList dso_init_list; + +static void init_lists(void) { static int inited; int i; @@ -40,6 +45,8 @@ static void init_types(void) QTAILQ_INIT(&init_type_list[i]); } + QTAILQ_INIT(&dso_init_list); + inited = 1; } @@ -48,7 +55,7 @@ static ModuleTypeList *find_type(module_init_type type) { ModuleTypeList *l; - init_types(); + init_lists(); l = &init_type_list[type]; @@ -62,20 +69,154 @@ void register_module_init(void (*fn)(void), module_init_type type) e = g_malloc0(sizeof(*e)); e->init = fn; + e->type = type; l = find_type(type); QTAILQ_INSERT_TAIL(l, e, node); } +void register_dso_module_init(void (*fn)(void), module_init_type type) +{ + ModuleEntry *e; + + init_lists(); + + e = g_malloc0(sizeof(*e)); + e->init = fn; + e->type = type; + + QTAILQ_INSERT_TAIL(&dso_init_list, e, node); +} + +static void module_load(module_init_type type); + void module_call_init(module_init_type type) { ModuleTypeList *l; ModuleEntry *e; + module_load(type); l = find_type(type); QTAILQ_FOREACH(e, l, node) { e->init(); } } + +#ifdef CONFIG_MODULES +static int module_load_file(const char *fname) +{ + GModule *g_module; + void (*sym)(void); + const char *dsosuf = HOST_DSOSUF; + int len = strlen(fname); + int suf_len = strlen(dsosuf); + ModuleEntry *e, *next; + int ret; + + if (len <= suf_len || strcmp(&fname[len - suf_len], dsosuf)) { + /* wrong suffix */ + ret = -EINVAL; + goto out; + } + if (access(fname, F_OK)) { + ret = -ENOENT; + goto out; + } + + assert(QTAILQ_EMPTY(&dso_init_list)); + + g_module = g_module_open(fname, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL); + if (!g_module) { + fprintf(stderr, "Failed to open module: %s\n", + g_module_error()); + ret = -EINVAL; + goto out; + } + if (!g_module_symbol(g_module, DSO_STAMP_FUN_STR, (gpointer *)&sym)) { + fprintf(stderr, "Failed to initialize module: %s\n", + fname); + /* Print some info if this is a QEMU module (but from different build), + * this will make debugging user problems easier. */ + if (g_module_symbol(g_module, "qemu_module_dummy", (gpointer *)&sym)) { + fprintf(stderr, + "Note: only modules from the same build can be loaded.\n"); + } + g_module_close(g_module); + ret = -EINVAL; + } else { + QTAILQ_FOREACH(e, &dso_init_list, node) { + register_module_init(e->init, e->type); + } + ret = 0; + } + + QTAILQ_FOREACH_SAFE(e, &dso_init_list, node, next) { + QTAILQ_REMOVE(&dso_init_list, e, node); + g_free(e); + } +out: + return ret; +} +#endif + +void module_load(module_init_type type) +{ +#ifdef CONFIG_MODULES + char *fname = NULL; + const char **mp; + static const char *block_modules[] = { + CONFIG_BLOCK_MODULES + }; + char *exec_dir; + char *dirs[3]; + int i = 0; + int ret; + + if (!g_module_supported()) { + fprintf(stderr, "Module is not supported by system.\n"); + return; + } + + switch (type) { + case MODULE_INIT_BLOCK: + mp = block_modules; + break; + default: + /* no other types have dynamic modules for now*/ + return; + } + + exec_dir = qemu_get_exec_dir(); + dirs[i++] = g_strdup_printf("%s", CONFIG_QEMU_MODDIR); + dirs[i++] = g_strdup_printf("%s/..", exec_dir ? : ""); + dirs[i++] = g_strdup_printf("%s", exec_dir ? : ""); + assert(i == ARRAY_SIZE(dirs)); + g_free(exec_dir); + exec_dir = NULL; + + for ( ; *mp; mp++) { + for (i = 0; i < ARRAY_SIZE(dirs); i++) { + fname = g_strdup_printf("%s/%s%s", dirs[i], *mp, HOST_DSOSUF); + ret = module_load_file(fname); + /* Try loading until loaded a module file */ + if (!ret) { + break; + } + g_free(fname); + fname = NULL; + } + if (ret == -ENOENT) { + fprintf(stderr, "Can't find module: %s\n", *mp); + } + + g_free(fname); + } + + for (i = 0; i < ARRAY_SIZE(dirs); i++) { + g_free(dirs[i]); + } + +#endif +} -- cgit v1.2.1